Short Answer:

To prevent cheese from leaking out of snacks like mozzarella sticks or samosas, keep the cheese cold or slightly frozen before cooking. This helps it stay solid longer while the outer coating crisps.

Also, avoid overcooking, ensure proper sealing of the edges, and use a suitable coating. Correct temperature and cooking time in an air fryer prevent the cheese from melting too quickly and leaking out.

Detailed Explanation:

Chilling the Cheese

One of the main ways to prevent cheese from leaking is to keep it cold or slightly frozen before cooking. Cold cheese takes longer to melt, allowing the outer coating to crisp and set before the cheese becomes too soft. For homemade mozzarella sticks or stuffed pastries, refrigerate or lightly freeze the cheese for 15–30 minutes before coating and cooking.

Proper Coating and Sealing
Make sure the snack is properly coated with breadcrumbs, pastry, or dough. For stuffed pastries, pinch or crimp the edges tightly to seal the filling inside. Any gaps or weak spots in the coating can allow cheese to escape while cooking. Using a thicker or double coating adds extra protection against leakage.

Correct Temperature
Cooking at the right temperature is crucial. Too high a temperature can cause the cheese to melt faster than the coating can crisp, leading to leaks. For mozzarella sticks in an air fryer, 200°C (390°F) is ideal, while puff or pastry snacks may require slightly lower temperatures around 170–180°C (340–350°F). This ensures even cooking and prevents cheese from escaping.

Timing and Monitoring
Avoid overcooking, as prolonged exposure to heat increases the risk of cheese leaking. Check halfway through the cooking process and flip or shake if needed to ensure even cooking. Adjust the time based on the size and thickness of the snack to achieve a crispy exterior while keeping the cheese inside intact.

Avoid Excess Moisture
Cheese with high moisture content is more likely to leak. Use firmer cheeses or drain softer cheeses before stuffing. Excess moisture can create steam inside the snack, softening the coating and allowing cheese to ooze out. Proper preparation ensures the filling stays contained during cooking.

Serving Tips
Serve snacks immediately after cooking. Waiting too long can cause residual heat to soften the cheese and weaken the outer coating, potentially leading to leaks. Proper handling and immediate serving maintain both texture and appearance.

Conclusion:

Preventing cheese from leaking requires cold or slightly frozen cheese, proper coating and sealing, correct temperature, careful timing, and controlling moisture. Following these steps ensures the outer layer crisps while the cheese melts perfectly inside, producing snacks that are golden, crispy, and visually appealing.